Method and polishing device for polishing a vehicle tyre

ABSTRACT

A method and polishing device for polishing a vehicle tire. An polishing agent application means is moved in relation to a tire of a stationary vehicle and polishing agent is applied on the side of the vehicle tire as the application means moves in relation to the tire of the stationary vehicle.

This is a Division of application Ser. No. 14/078,088 filed Nov. 12,2013, which claims the benefit of and priority to European PatentApplication No. 13167571.2 filed May 14, 2013 and Finish PatentApplication No. 20126317 filed Dec. 17, 2012. The disclosures of theprior applications are hereby incorporated by reference herein in theirentireties.

BACKGROUND OF THE INVENTION

The invention relates to polishing a vehicle tyre.

Various automatically operated washing apparatuses are used inautomatically washing vehicles. The washing apparatus may comprise oneor more fixedly positioned washing devices, for instance, in relation towhich a vehicle moves while the washing device washes the surface orpart of the vehicle facing the washing device. The washing apparatus mayalso comprise one or more movably positioned washing devices that arearranged to move in relation to a stationary vehicle.

The washing apparatuses described above may also have a polishing devicefor polishing the side of a vehicle tyre. A known polishing device haslong foam-plastic pieces which are fixed to a floor structure and towhich polishing agent is sprayed from the inside. As the vehicle movesthrough the polishing device, the foam-plastic pieces are pressedagainst the side of the tyre in its bottom part, whereby the polishingagent rubs onto the tyre. The side of the tyre on its entirecircumference is polished as, while the vehicle moves forward, the tyrerotates at least once around its entire circumference with thefoam-plastic pieces pressing against the side of the tyre in its bottompart.

In another known polishing device, said foam-plastic pieces are replacedby long and narrow rotating brushes in the longitudinal direction of thevehicle. Polishing agent is sprayed to the rotating brush that rubs itinto the side of the tyre in its bottom part. In this solution, too, theside of the tyre on its entire circumference is polished as, while thevehicle moves forward, the tyre rotates at least once around its entirecircumference with the brushes pressing against the side of the tyre inits bottom part.

A third known polishing device has a spray nozzle arranged on a guiderail fastened to the floor. As the vehicle moves forward through thepolishing device, the spray nozzles also moves forward on its guide railwith the vehicle tyre and sprays polishing agent on the side of the tyrein its bottom part. The side of the tyre on its entire circumference ispolished as, while the vehicle moves forward, the tyre rotates at leastonce around its entire circumference with the spray nozzle sprayingpolishing agent on the side of the tyre in its bottom part.

A fourth known polishing device comprises in the longitudinal directionof a vehicle several consecutively positioned fixed spray nozzles forspraying polishing agent on the tyre. The polishing device furthercomprises a switch runner which is positioned on the floor and on whichthe vehicle moves forward. As the tyre of the vehicle arrives at aspecific switch in the switch runner, the spray nozzle corresponding tosaid switch sprays polishing agent on the side of the tyre in its bottompart. The side of the tyre on its entire circumference is polished as,while the vehicle moves forward, the tyre rotates at least once aroundits entire circumference, and as the vehicle tyre arrives at a switch onthe switch runner, the switch directs the corresponding spray nozzle tospray polishing agent on the side of the tyre in its bottom part.

BRIEF DESCRIPTION OF THE INVENTION

The object of this invention is to develop a novel type of method andpolishing device for polishing a vehicle tyre.

In the method for polishing a vehicle tyre in accordance with theinvention, at least one vehicle tyre polishing agent application meansis moved in relation to a tyre of a stationary vehicle and polishingagent is applied on the side of the vehicle tyre as the applicationmeans moves in relation to the tyre of the stationary vehicle.

The polishing device for polishing a vehicle tyre in accordance with theinvention comprises at least one application means for applyingpolishing agent on the side of a vehicle tyre, the application meansbeing arranged to move in relation to the tyre of the stationaryvehicle.

In the solution, at least one polishing agent application means for avehicle tyre is moved in relation to a tyre of a stationary vehicle andthe polishing agent is applied to the side of the vehicle tyre as thepolishing agent application means moves in relation to the tyre of thestationary vehicle.

The solution may be implemented with a structurally simple and thus alsoreliable polishing device that may be an independently operating deviceor that may easily be integrated as part of a portal type washingapparatus, for instance, in which case the solution is easy to take intouse through retrofitting into washing apparatuses already in use. At thesame time, it is possible to avoid a problem that occurs in someprior-art solutions, that is, the extension of the length of the spacereserved for the washing apparatus or of the wash tunnel due to the factthat that it is necessary to reserve an extra distance of at least aboutthree meters for the polishing device so that the vehicle tyre canrotate at least once around as the vehicle moves forward during thepolishing of the tyre.

Some embodiments of the solution are disclosed in the dependent claims.

According to an embodiment, the application means for the polishingagent of a vehicle tyre is moved in relation to the tyre of a stationaryvehicle along an annular path formed by the side of the vehicle tyre.

According to an embodiment, the polishing agent is applied to the sideof a vehicle tyre by spraying it on the vehicle tyre.

According to an embodiment, the polishing agent spray is directed to avehicle tyre as a narrow fan-shaped spray.

According to an embodiment, the spray distance of the polishing agentfrom a vehicle tyre is altered on the basis of the tyre size and/orprofile.

According to an embodiment, the rim of a vehicle tyre is covered duringthe application of the polishing agent to prevent the polishing agentfrom spreading on the rim of the vehicle tyre.

BRIEF DESCRIPTION OF THE FIGURES

The invention will now be described in greater detail by means ofpreferred embodiments, with reference to the accompanying drawings, inwhich:

FIG. 1 is a schematic front view of a vehicle washing apparatus with avehicle tyre polishing device connected thereto,

FIG. 2 is a schematic front view of a part of FIG. 1,

FIG. 3 is a schematic side view of a vehicle tyre,

FIGS. 4 and 5 are schematic diagonal front views of a vehicle tyrewashing device with a vehicle tyre polishing device arranged thereto,

FIG. 6 is a schematic diagonal back view of the vehicle tyre washingdevice according to FIGS. 4 and 5, and

FIG. 7 is a schematic diagonal front view of a second vehicle tyrepolishing device.

In the figures, some embodiments of the invention are shown simplifiedfor the sake of clarity. Like reference numerals identify like elementsin the figures.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic front view of a vehicle 1 washing apparatus 3 witha vehicle 1 tyre 2 polishing device 9, and FIG. 2 is a schematic frontview of a part of FIG. 1. The washing apparatus 3 of FIG. 1 comprises aportal-type framework 4 that is arranged to move on rails, for instance,on site in such a manner that during the washing of a vehicle 1, theframework 4 of the washing apparatus 3 moves in the longitudinaldirection of the vehicle 1 while the vehicle 1 remains stationary. Forthe sake of clarity, said rails and means for moving the framework 4 ofthe washing apparatus 3 on said rails are not shown in the figures.

The washing apparatus 3 of FIG. 1 consists of a roof unit 5 that issupported on the framework 4 and in the washing apparatus 3 of FIG. 1forms a vehicle 1 washing device that is intended to wash the upwarddirected surfaces of the vehicle and possibly the front and rear ends ofthe vehicle. The roof unit 5 comprises a washing brush 6 and its axle 7that may be rotated by means of an electric motor not shown in FIG. 1for the sake of clarity. The washing apparatus 3 of FIG. 1 also includesair nozzles 8 for drying the vehicle 1 by blow drying, that is, byblowing air toward the vehicle 1. The washing apparatus 3 may alsoinclude other washing devices, such as brushes and electric motors torotate them for washing the sides of the vehicle 1. In addition to orinstead of the washing devices equipped with brushes for washing thesides of a car, the washing apparatus 3 may comprise washing devicesequipped with washing nozzles for brushless washing of vehicles 1. Thegeneral structure and operational principle of automatically operatedwashing apparatuses of this type, which are arranged to move in relationto a stationary vehicle, are known per se to a person skilled in the artand will not be described in more detail herein.

FIG. 1 also shows a polishing device 9 for polishing the vehicle 1 tyre2, in practice, for polishing the side 2′ of the vehicle 1 tyre 2. Thepolishing of the side 2′ of the vehicle 1 tyre 2 is typically doneduring the washing of the vehicle 1, either simultaneously with thewashing of the vehicle or immediately thereafter.

The polishing device 9 includes spray nozzles 10 located on both sidesof the vehicle 1 and arranged to direct the polishing agent spray 11 tothe tyre 2 of the vehicle. The spray nozzles 10 are arranged at theoutermost end 12′ of a nozzle arm 12 that is in the direction of theradius of the vehicle 1 tyre 2. The nozzle arm 12 is a tubularstructure, in which the inside of the nozzle arm 12 forms a flow channelfor supplying polishing agent through the nozzle arm 12 to the spraynozzle 10 in a manner to be described later. The spray nozzle 10 can bea separate part attached to the outermost end 12′ of the nozzle arm 12,or the spray nozzle 10 can also be achieved merely by the structuraldesign of the outermost end 12′ of the nozzle arm 12.

The polishing device 9 also includes a rotating motor 13, to which thenozzle arm 12 is arranged through the inner end 12″ of the nozzle arm 12in such a manner that the rotating motor 13 may rotate the spray nozzle10 at the outermost end 12′ of the nozzle arm 12 along an annular path.

The polishing agent is conveyed, fed by a pump 15, to the spray nozzles10 from the polishing agent container 14 through a connecting tube 16,manifold 17, supply channels 18 and nozzle arms 12, the inner end 12′ ofthe nozzle arms 12 being in flow connection with the supply channels 18.The nozzle arm 12 is connected to the supply channel 18 by a rotatingconnector. The supply channels 18 are connected to the manifold 17 thatis connected through a connecting tube 16 and pump 15 to the polishingagent container 14. The polishing agent sprays 11 are provided by meansof pressure generated by the pump 15, and the spray nozzles 10 directthe polishing agent spray 11 to the tyre 2 of the vehicle. The operationof the pump 15 is controlled by a control unit 19 that is connected tothe pump 15 via a control line 20 that is shown as an arrow 20 from thecontrol unit 19 to the pump 15. The operation of the rotating motor 13is also controlled by a control unit 19 that is connected to therotating motor 13 via a control line 21 that is shown as an arrow 21from the control unit 19 to the rotating motor 13.

When using the polishing device 9, the control unit 19 is arranged tostart the pump 15 when the polishing device 9 and especially the spraynozzles 10 are at the location of the tyre 2. The control unit 19 mayobtain information on the location of the tyre from a special detectionunit that detects the location of the tyre and may be part of thepolishing device 9 or washing apparatus 3. Simultaneously, the controlunit 19 also starts the rotating motor 13, whereby the spray nozzle 10at the outermost end 12′ of the nozzle arm 12 rotates as shownschematically in FIG. 3 in the rotating direction shown by arrow R, forinstance, along a path 22 in the shape of the vehicle 1 tyre 2 andsprays polishing agent to the side 2′ of the tyre 2. The spray nozzle 10is rotated at least once, but preferably at least twice or more aroundthe circumference of the vehicle 1 tyre 2. To achieve a good polishingresult, the tyre is washed before polishing. If the side 2′ of thevehicle 1 tyre 2 is washed before applying the polishing agent on theside 2′ of the tyre 2, only one or a few spray nozzle 10 rounds, 2 to 4,for example, around the circumference of the tyre 2 suffice to achieve agood polishing result. After the spray nozzle 10 has been rotated aspecific number of rounds around the circumference of the tyre 2, thecontrol unit 19 stops the rotating motor 13 and pump 15. While the tyreis being polished, both the vehicle 1 and the framework 4 of the washingapparatus 3, to which at least some of the parts belonging to thepolishing device 9 are arranged, remain stationary.

FIG. 3 is a schematic view of the spray nozzle 10 rotatingcounter-clockwise, but the rotation direction of the spray nozzle 10 maynaturally also be clockwise.

In the embodiment shown in FIGS. 1 and 2, the spray nozzles 10, nozzlearms 12, rotating motors 13, polishing agent container 14, connectingtube 16, manifold 17, supply channels 18 and control unit 19 thus form apolishing device 9 for polishing a vehicle 1 tyre 2 with the spraynozzles 10 forming the actual application means of the polishing device9 for applying the polishing agent to the tyre and the other partsforming means for supplying the polishing agent to the spray nozzles 10or means for rotating the spray nozzles in relation to the tyre 2 of thestationary vehicle 1. In the embodiment of FIGS. 1 and 2, the polishingdevice 9 is arranged as part of the washing apparatus 3. However, thepolishing device 9 could also be implemented as a device that isentirely separate from the washing apparatus 3.

In the polishing device 9 shown in FIG. 1, the spray nozzles 10 formpolishing agent application means for applying the polishing agent tothe side 2′ of the vehicle 1 tyre 2. Instead of the spray nozzles 10,one or more brushes or sponges for applying polishing agent on the side2′ of the vehicle 1 tyre 2 could also be used to apply the polishingagent to the side 2′ of the vehicle 1 tyre 2, and said brush or spongewould rub the polishing agent supplied through the supply channel 18 andfastening arm of the brush or sponge corresponding to the nozzle arm 12to the side of the tyre.

FIGS. 4 and 5 are schematic diagonal front views of a vehicle 1 tyrewashing device 25 with a vehicle 1 tyre 2 polishing device 9 arrangedthereto, and FIG. 6 is a schematic diagonal back view of the vehicle 1tyre washing device 25 according to FIGS. 4 and 5. The vehicle 1 tyrewashing device 25 comprises a framework 26 and, as seen in FIGS. 4 and5, a first carriage 27 supported to the top part of the framework 26 anda second carriage 28 supported to the top part of the first carriage 27in such a manner that the first carriage 27 can move in the directionshown schematically by arrow A in relation to the framework 26 and thesecond carriage 28 can move in the direction shown schematically byarrow A in relation to both the framework 26 and the first carriage 27.At the end of the second carriage 27, a backing plate 29 is attachedwith a tyre washing brush 30 fastened to it, and feed openings 31 arearranged in the mid-section of the brush in such a manner that tyrewashing water and agent can be fed through the tyre washing brush 30between the tyre washing brush 30 and vehicle tyre. For the sake ofclarity, FIGS. 4 to 6 do not show individual bristles of the tyrewashing brush 30. The tyre washing device 25 further comprises arotating motor 13 for rotating the backing plate 29 and the tyre washingbrush 30 fastened thereto during the washing of the vehicle tyre forinstance in the direction shown schematically by arrow R in FIG. 5 orback and forth.

The tyre washing device 25 of FIGS. 4 to 6 further comprises a nozzlearm 12 located on the back side of the backing plate 29, as seen inrelation to the tyre washing brush 30, with a spray nozzle 10 arrangedat its outermost end 12′ for spraying polishing agent on the side 2′ ofthe vehicle 1 tyre 2. The spray nozzle 10 arranged at the outermost end12′ of the nozzle arm 12 is arranged to settle on the back side of thebacking plate 29 on its outer circumference, and borings 32 and 33 arearranged on the outer circumference of the backing plate 29 as well ason the outer circumference of the tyre washing brush 30 in such a mannerthat the spray nozzle 10 on the outermost end 12′ of the nozzle arm 12resides inside the outer circumference of both the backing plate 29 andtyre washing brush 30. For the sake of clarity, FIGS. 4 to 6 do not showthe supply channel 18, pump 15, polishing agent container 14 or controlunit 19 connected to the spray nozzle 10 and nozzle arm 12. Theinnermost end 12″ of the nozzle arm 12 can be arranged to the motor 13or backing plate 29, for instance.

The operating principle of the tyre washing device 25 according to FIGS.4 to 6 is essentially as follows. When starting the washing of a vehicle1 tyre 2, feed carriages 27 and 28 are suitably moved with respect tothe framework 26 and/or each other in such a manner that the tyrewashing brush 30 of the tyre washing device 25 moves toward the vehicle1 tyre 2 to be washed. When the tyre washing brush 30 comes into contactwith the tyre 2 or preferably slightly before the tyre washing brush 30comes into contact with the tyre 2, washing water supply is startedthrough the tyre washing brush 30 and the rotating motor 13 is started,whereby the tyre washing brush 30 begins to rotate in relation to thetyre 2. After this, the tyre washing brush 30 is pressed against thetyre 2 and its rim 23 while the tyre washing brush 30 is rotated andwashing water is supplied through the tyre washing brush 30. When thetyre washing program made for the tyre washing device 25 is completed,washing water supply through the tyre washing brush 30 is stopped andthe tyre washing brush 30 is moved away from the tyre 2 by suitablymoving the feed carriages 27 and 28 with respect to the framework 26and/or each other.

After the tyre is washed, the side 2′ of the tyre 2 can be polished withthe polishing agent. To start polishing the tyre, the pump 15 is startedto supply the polishing agent from the polishing agent container 14 tothe spray nozzle 10. The rotating motor 13, if it was switched off afterthe tyre washing, is started again, in which case the backing plate 29and with it, the tyre washing brush 30, nozzle arm 12 and spray nozzle10 also start to rotate in relation to the tyre 2. Polishing agent issprayed from the spray nozzle 10 through the boring 32 in the backingplate 29 and the boring 33 in the tyre washing brush 30 toward the side2′ of the tyre 2 past the bristles in the tyre washing brush 30, wherebythe spray nozzle 10 provides a polishing agent spray 11 toward the side2′ of the tyre 2 as shown schematically in FIG. 5. As the motor 13rotates, the spray nozzle 10 moves in relation to the tyre 2 along anannular path 22 shown schematically in FIG. 3 and sprays polishing agenton the side 2′ of the tyre 2. The entire side of the tyre 2 is polishedwhen the spray nozzle 10 rotates at least once around the circumferenceof the tyre 2, as already stated earlier.

According to an embodiment, prior to starting to apply the polishingagent, the tyre washing brush 30 is moved into contact with the vehicle1 tyre 2 in such a manner that the tyre washing brush 30 presses lightlyagainst the rim 23 of the vehicle 1 tyre 2. The tyre washing brush 30can be moved toward the vehicle 1 tyre 2 by suitably moving the feedcarriages 27 and 28 with respect to the framework 26 and/or each othertoward the tyre 2, if the tyre washing brush 30 has already been movedaway from the tyre 2 after washing the tyre 2. Alternatively, if thetyre washing brush 30 is still in contact with the tyre 2 after the tyre2 has been washed, the tyre washing brush 30 can be moved slightly awayfrom the tyre 2. The force, with which the tyre washing brush 30 ispressed against the rim 23 of the tyre 2 during polishing, may be thesame as used during tyre washing, in which only the rim 23 of the tyre 2was washed. The bristles of the tyre washing brush 30 then essentiallycover only the rim 23 of the tyre 2 and do not extend to the area of theside 2′ of the tyre 2. Alternatively, if, during the washing of the tyre2, the side 2′ of the tyre 2 was also washed, in which case the tyrewashing brush 30 was pressed against the tyre 2 using a force that bentthe bristles of the tyre washing brush 30 against the side 2′ of thetyre 2, the tyre washing brush 30 could be pulled slightly away from thetyre 2 so that the bristles of the tyre washing brush 30 essentiallycover only the rim 23 of the tyre 2.

As the tyre washing brush 30 presses against the rim 23 of the vehicle 1tyre 2, the bristles of the tyre washing brush 30 cover the rim 23 ofthe vehicle 1 tyre 2, whereby the tyre washing brush 30 prevents thepolishing agent spray from ending up on the rim 23 of the tyre 2. Inthis embodiment, the tyre washing brush 30 forms a means for preventingthe application of the polishing agent on the rim 23 of the vehicle 1tyre 2 by covering the rim 23 of the vehicle 1 tyre 2 during theapplication of the polishing agent. After the polishing agent has beenapplied to the side 2′ of the tyre 2, the tyre washing brush 30 can bemoved away from the tyre 2 by moving the carriages 27 and 28 to theposition where they are when the tyre washing device 25 is not used.

In the solution of FIGS. 4 to 6, the tyre polishing device 9 is thusconnected to the tyre washing device 25 at least in respect of somecomponents, such as the nozzle arm 12 and spray nozzle 10. The tyrewashing device 25 can be arranged to be part of a washing apparatus thatmay also comprise other devices intended for washing or drying a vehicleand that moves in relation to a stationary vehicle. The tyre washingdevice 25 can also be an independent device separate from other devicesintended for washing or drying a vehicle. In both cases, one of the tyrewashing devices 25 shown herein is preferably positioned on each side ofthe vehicle.

The spray nozzle 10 is preferably selected so as to provide the flatfan-shaped spray shown schematically in FIG. 5. The spread angle of thespray nozzle 10 may be 25 to 50 degrees, for example. The spread angleof the nozzle may be dimensioned proportional to the used spraypressure, whereby a specific nominal pressure uses a specific spreadangle.

In the solution of FIGS. 4 to 6, it is possible to affect the spraydistance formed between the tyre 2 side 2′ and spray nozzle 10 by movingthe carriages 27 and 28 in relation to the framework 26 and/or eachother. By varying the spray distance and also the spray pressure, it ispossible to affect the force or pressure, with which the polishing agentspray 11 hits the side 2′ of the tyre 2. Further, the possibility ofchanging the spray distance makes it possible to affect the width of thepolishing spray at the side 2′ of the tyre 2, whereby it is possible toensure that the width of the polishing spray at the side 2′ of the tyre2 corresponds essentially to the dimension of the side 2′ of the tyre 2in the radial direction of the tyre 2. The side 2′ of the tyre 2 willthen be essentially entirely treated with the polishing agent in such amanner, however, that the polishing agent does not essentially reach thetyre space, the rim 23 of the tyre 2 or the side of the vehicle 1. Byaltering the spray distance, it is thus possible to easily polish tyresof different diameter and/or profile with the same polishing device. Inthe example of FIGS. 1 and 2, the polishing device 9 is fixed to thewashing apparatus 3, but the polishing device according to FIGS. 1 and 2can also be arranged to be movable with respect to the framework 4 ofthe washing apparatus 3 in such a manner that the distance of the spraynozzle from the tyre 2 of the vehicle 1 can be altered on the basis ofthe tyre size and/or profile.

FIG. 7 is a schematic diagonal front view of a second vehicle 1 tyre 2polishing device 9. The polishing device 9 shown in FIG. 7 resembles thetyre washing device 25 shown in FIGS. 4 and 5 otherwise, except that thepolishing device 9 shown in FIG. 7 does not comprise a tyre washingbrush 30, but the tyre washing brush 30 has been replaced by a guardring 34 that will be described later in more detail.

In the manner of FIGS. 4 and 5, the polishing device 9 shown in FIG. 7comprises a framework 26, a first carriage 27 supported to the top partof the framework 26 and a second carriage 28 supported to the top partof the first carriage 27 in such a manner that the first carriage 27 canmove with respect to the framework 26 and the second carriage 28 canmove with respect to both the framework 26 and first carriage 27. Abacking plate 29 is attached to the end of the second carriage 28. Thepolishing device 9 further comprises a nozzle arm 12 with a spray nozzle10 arranged at its outermost end 12′ for spraying polishing agent on theside 2′ of the vehicle 1 tyre 2. The innermost end 12″ of the nozzle arm12 can be arranged to the motor 13 or backing plate 29, for instance.The polishing device 9 shown in FIG. 7 further comprises a guard ring 34arranged with bearings to the outer circumference of the backing plate29 in such a manner that the backing plate 29 can turn with respect tothe stationary guard ring 34, when the guard ring 34 is pressed againstthe rim 23 of the vehicle 1 tyre 2 during the polishing of the tyre 2,as will be described in more detail later. The guard ring 34 is arrangedto extend around the entire outer circumference of the backing plate 29and to a distance outward from the backing plate 29, away from theframework 26 of the polishing device 9.

When using the polishing device 9 according to FIG. 7 to polish the side2′ of a vehicle 1 tyre 2, the guard ring 34 is moved toward the vehicle1 tyre 2 in such a manner that the guard ring 34 presses lightly againstthe rim 23 of the vehicle 1 tyre 2 and surrounds the rim 23 of the tyre2. The guard ring 34 can be made of soft rubber, for example, so thatthe guard ring 34 does not damage the rim 23. The guard ring 34 can bemoved toward the vehicle 1 tyre 2 by suitably moving the feed carriages27 and 28 in relation to the framework 26 and/or each other toward thetyre 2. As the guard ring 34 presses lightly against the rim 23 of thevehicle 1 tyre 2, the guard ring 34 covers the rim 23 of the vehicle 1tyre 2, whereby the guard ring 34 prevents the polishing agent sprayfrom ending up on the rim 23 during the application of the polishingagent. When the backing plate 29 and spray nozzle 10 of the polishingdevice 9 rotate in relation to the tyre 2 during the application of thepolishing agent, the guard ring 34 remains in place in relation to thetyre 2 by means of the bearings between the guard ring 34 and backingplate 29, and the guard ring 34 does not rotate with respect to the tyre2 and, thus, cannot scratch the rim 23. In the embodiment shown in FIG.7, the guard ring 34 thus forms a means that prevents the application ofthe polishing agent on the rim 23 of the vehicle 1 tyre 2 by coveringrim 23 of the vehicle 1 tyre 2 during the application of the polishingagent. On the outward facing surface of the backing plate 29, in thearea defined by the guard ring 34, it is possible to arrange a plasticguard plate, for instance, to prevent the backing plate 29 from cominginto contact with the parts of the tyre 2 rim 23, if the centre of therim 23 comprises parts extending outward from the rim 23, for instance.

In the examples shown in the figures, the polishing device 9 comprisesonly one spray nozzle 10 on both sides of the vehicle 1. However, thepolishing device 1 can also comprise more than one spray nozzle 10, twoor three spray nozzles, for example, on both sides of the vehicle 1. Thespray nozzles 10 on the same side of the vehicle 1 can then be arrangedin such a manner that they are around the circumference of a ring at adistance from each other. Similarly, it is possible to place one or moreof the above-mentioned sponges or brushes useable instead of the spraynozzles 10 on both sides of the vehicle.

The present polishing devices 9 are simple in structure and, thus,reliable. As already stated above, the present polishing devices 9 canbe implemented as devices that are entirely separate from the washingapparatus 3 or they can easily be integrated as part of a portal-typewashing apparatus, for example, in which case they are also easy toretrofit into washing apparatuses already in use. At the same time, itis possible to avoid a problem arisen in at least some of the knownsolutions, that is, the increase in the space reserved for the washingapparatus or in the length of the wash tunnel, when it has beennecessary to reserve approximately 2 to 3 meters extra space for thepolishing device.

After the polishing agent has been applied to the sides 2′ of thevehicle 1 tyres 2, the polishing agent that has possibly ended up on thesides and rims of the vehicle can be removed. The polishing agent thathas possibly ended up on the sides and rims of the vehicle can beremoved for instance by spraying drying wax on the vehicle and thenblowing drying air against the vehicle. The drying wax flushes thepolishing agent away from the sides of the vehicle 1 and the rims 23 ofthe tyres, but the polishing agent remains on the sides of the tyres.The drying wax can be sprayed on the surface and tyres of the vehiclefrom drying wax nozzles 24 arranged on the framework 4 of the washingapparatus 3 shown in FIG. 1, for example, and the drying air can beblown against the vehicle from air nozzles 8 shown in FIG. 1, forexample.

In the embodiment of FIG. 1, the polishing device 9 is connected to aportal-type washing apparatus 3 that comprises both washing devices forwashing a vehicle and drying devices for drying a vehicle. The presentpolishing devices 9 could also be connected to a washing apparatus 3with no portal-type framework, in which case the washing devices forwashing the sides of a vehicle and the drying devices for drying thesides of a vehicle are positioned on vertical poles on both sides of thevehicle, and the means for washing and drying the upward facing surfacesof the vehicle and possibly the front and rear ends of the vehicle canbe supported to the ceiling structures of the washing location, forinstance. The present polishing devices 9 can also be placed inconnection with a drying apparatus intended solely for drying a vehicleand comprising means for blowing drying air toward the vehicle. Themeans for applying the drying wax can then be placed either on the samedrying apparatus or on another structure of the washing or dryinglocation before said drying equipment. When placing the polishing device9 in connection with washing or drying apparatus, the structure of saidwashing or drying apparatus may also be of some other type than thatpresented above.

According to an embodiment, the polishing device may comprise either oneapplication means or two or more application means placed side by sidein the vertical or horizontal direction, which are preferably spraynozzles. In this embodiment, said one or more application means aremoved at the location of the vehicle tyre in relation to the tyre of thestationary vehicle in either horizontal direction, that is, in thelongitudinal direction of the vehicle, or in the vertical direction,that is, in the elevation of the vehicle, while simultaneously supplyingpolishing agent through the application means to the tyre of thevehicle. The polishing agent is thus applied on a rectangular area,inside the outline of which the tyre being polished is located. It isalso possible that the polishing agent is applied through only onestationary spray nozzle. The polishing agent that has ended up on therim of the tyre and possibly on the side of the vehicle can be removedas described above.

In some cases, the features disclosed in this specification may be usedas such, regardless of other features. On the other hand, the featuresdisclosed in this specification may, when necessary, be combined to formvarious combinations.

It is obvious to a person skilled in the art that as technologyadvances, the basic idea of the invention may be implemented in manydifferent ways. The drawings and the related description are onlyintended to illustrate the idea of the invention. The invention may varyin detail within the scope of the claims.

The invention claimed is:
 1. A polishing device for polishing a vehicletyre, the polishing device comprising: a backing plate; at least onepolishing agent applicator configured for applying polishing agent on aside of the vehicle tyre, the at least one polishing agent applicatorbeing arranged to move in relation to the vehicle tyre of a stationaryvehicle; and a guard ring arranged with bearings at the outercircumference of the backing plate, such that the backing plate can turnwith respect to the guard ring when the guard ring is pressed against arim of the vehicle tyre during polishing of the vehicle tyre, and theguard ring remains stationary during the application of the polishingagent, wherein the guard ring is configured for covering the rim of thevehicle tyre during the application of the polishing agent to preventthe application of the polishing agent on the rim of the vehicle tyre,wherein the guard ring is configured to extend a distance outwardrelative to the polishing device and toward the rim of the vehicle tyre,wherein the at least one polishing agent applicator is a nozzle armincluding a spray nozzle arranged at the outermost end of the nozzlearm, the spray nozzle being configured for spraying polishing agent onthe tyre of the vehicle, and wherein the at least one polishing agentapplicator is arranged to move in relation to the tyre of a stationaryvehicle along an annular path formed by the side of the vehicle tyre. 2.The polishing device according to claim 1, wherein the guard ringcomprises a soft rubber material.
 3. The polishing device as claimed inclaim 1, wherein the polishing device comprises at least one pump forfeeding polishing agent to the at least one polishing agent applicatorand at least one motor for moving the at least one polishing agentapplicator in relation to the tyre of a stationary vehicle.
 4. Thepolishing device as claimed in claim 1, wherein the spray nozzle isarranged to direct the polishing agent to the vehicle tyre as a narrowfan-shaped spray.
 5. The polishing device as claimed in claim 1, whereinthe spread angle of the spray nozzle is 25 to 50 degrees.
 6. Thepolishing device as claimed in claim 1, further comprising: a framework;a first carriage supported at the top part of the framework; a secondcarriage supported at the top part of the first carriage such that thefirst carriage can move with respect to the framework and the secondcarriage can move with respect to both the framework and the firstcarriage, wherein the backing plate is attached to an end of the secondcarriage.